Cefepime-Taniborbactam in Complicated Urinary Tract Infection.

BACKGROUND: Carbapenem-resistant Enterobacterales species and multidrug-resistant Pseudomonas aeruginosa are global health threats. Cefepime-taniborbactam is an investigational ß-lactam and ß-lactamase inhibitor combination with activity against Enterobacterales species and P. aeruginosa expressing serine and metallo-ß-lactamases. METHODS: In this phase 3, double-blind, randomized trial, we assigned hospitalized adults with complicated urinary tract infection (UTI), including acute pyelonephritis, in a 2:1 ratio to receive intravenous cefepime-taniborbactam (2.5 g) or meropenem (1 g) every 8 hours for 7 days; this duration could be extended up to 14 days in case of bacteremia. The primary outcome was both microbiologic and clinical success (composite success) on trial days 19 to 23 in the microbiologic intention-to-treat (microITT) population (patients who had a qualifying gram-negative pathogen against which both study drugs were active). A prespecified superiority analysis of the primary outcome was performed after confirmation of noninferiority. RESULTS: Of the 661 patients who underwent randomization, 436 (66.0%) were included in the microITT population. The mean age of the patients was 56.2 years, and 38.1% were 65 years of age or older. In the microITT population, 57.8% of the patients had complicated UTI, 42.2% had acute pyelonephritis, and 13.1% had bacteremia. Composite success occurred in 207 of 293 patients (70.6%) in the cefepime-taniborbactam group and in 83 of 143 patients (58.0%) in the meropenem group. Cefepime-taniborbactam was superior to meropenem regarding the primary outcome (treatment difference, 12.6 percentage points; 95% confidence interval, 3.1 to 22.2; P = 0.009). Differences in treatment response were sustained at late follow-up (trial days 28 to 35), when cefepime-taniborbactam had higher composite success and clinical success. Adverse events occurred in 35.5% and 29.0% of patients in the cefepime-taniborbactam group and the meropenem group, respectively, with headache, diarrhea, constipation, hypertension, and nausea the most frequently reported; the frequency of serious adverse events was similar in the two groups. CONCLUSIONS: Cefepime-taniborbactam was superior to meropenem for the treatment of complicated UTI that included acute pyelonephritis, with a safety profile similar to that of meropenem. (Funded by Venatorx Pharmaceuticals and others; CERTAIN-1 ClinicalTrials.gov number, NCT03840148.).

Unravelling the collateral damage of antibiotics on gut bacteria.

Antibiotics are used to fight pathogens but also target commensal bacteria, disturbing the composition of gut microbiota and causing dysbiosis and disease1. Despite this well-known collateral damage, the activity spectrum of different antibiotic classes on gut bacteria remains poorly characterized. Here we characterize further 144 antibiotics from a previous screen of more than 1,000 drugs on 38 representative human gut microbiome species2. Antibiotic classes exhibited distinct inhibition spectra, including generation dependence for quinolones and phylogeny independence for ß-lactams. Macrolides and tetracyclines, both prototypic bacteriostatic protein synthesis inhibitors, inhibited nearly all commensals tested but also killed several species. Killed bacteria were more readily eliminated from in vitro communities than those inhibited. This species-specific killing activity challenges the long-standing distinction between bactericidal and bacteriostatic antibiotic classes and provides a possible explanation for the strong effect of macrolides on animal3-5 and human6,7 gut microbiomes. To mitigate this collateral damage of macrolides and tetracyclines, we screened for drugs that specifically antagonized the antibiotic activity against abundant Bacteroides species but not against relevant pathogens. Such antidotes selectively protected Bacteroides species from erythromycin treatment in human-stool-derived communities and gnotobiotic mice. These findings illluminate the activity spectra of antibiotics in commensal bacteria and suggest strategies to circumvent their adverse effects on the gut microbiota.

Bacterial Heterogeneity and Antibiotic Survival: Understanding and Combatting Persistence and Heteroresistance.

For decades, mankind has dominated the battle against bacteria, yet the tide is slowly turning. Our antibacterial strategies are becoming less effective, allowing bacteria to get the upper hand. The alarming rise in antibiotic resistance is an important cause of anti-infective therapy failure. However, other factors are at play as well. It is widely recognized that bacterial populations display high levels of heterogeneity. Population heterogeneity generates phenotypes specialized in surviving antibiotic attacks. Nonetheless, the presence of antibiotic-insensitive subpopulations is not considered when initiating treatment. It is therefore time to reevaluate how we combat bacterial infections. We here focus on antibiotic persistence and heteroresistance, phenomena in which small fractions of the population are tolerant (persisters) and resistant to antibiotics, respectively. We discuss molecular mechanisms involved, their clinical importance, and possible therapeutic strategies. Moving forward, we argue that these heterogeneous phenotypes should no longer be ignored in clinical practice and that better diagnostic and therapeutic approaches are urgently needed.

Gamblers: An Antibiotic-Induced Evolvable Cell Subpopulation Differentiated by Reactive-Oxygen-Induced General Stress Response.

Antibiotics can induce mutations that cause antibiotic resistance. Yet, despite their importance, mechanisms of antibiotic-promoted mutagenesis remain elusive. We report that the fluoroquinolone antibiotic ciprofloxacin (cipro) induces mutations by triggering transient differentiation of a mutant-generating cell subpopulation, using reactive oxygen species (ROS). Cipro-induced DNA breaks activate the Escherichia coli SOS DNA-damage response and error-prone DNA polymerases in all cells. However, mutagenesis is limited to a cell subpopulation in which electron transfer together with SOS induce ROS, which activate the sigma-S (σS) general-stress response, which allows mutagenic DNA-break repair. When sorted, this small σS-response-"on" subpopulation produces most antibiotic cross-resistant mutants. A U.S. Food and Drug Administration (FDA)-approved drug prevents σS induction, specifically inhibiting antibiotic-promoted mutagenesis. Further, SOS-inhibited cell division, which causes multi-chromosome cells, promotes mutagenesis. The data support a model in which within-cell chromosome cooperation together with development of a "gambler" cell subpopulation promote resistance evolution without risking most cells.

Inhaled Amikacin to Prevent Ventilator-Associated Pneumonia.

BACKGROUND: Whether preventive inhaled antibiotics may reduce the incidence of ventilator-associated pneumonia is unclear. METHODS: In this investigator-initiated, multicenter, double-blind, randomized, controlled, superiority trial, we assigned critically ill adults who had been undergoing invasive mechanical ventilation for at least 72 hours to receive inhaled amikacin at a dose of 20 mg per kilogram of ideal body weight once daily or to receive placebo for 3 days. The primary outcome was a first episode of ventilator-associated pneumonia during 28 days of follow-up. Safety was assessed. RESULTS: A total of 850 patients underwent randomization, and 847 were included in the analyses (417 assigned to the amikacin group and 430 to the placebo group). All three daily nebulizations were received by 337 patients (81%) in the amikacin group and 355 patients (83%) in the placebo group. At 28 days, ventilator-associated pneumonia had developed in 62 patients (15%) in the amikacin group and in 95 patients (22%) in the placebo group (difference in restricted mean survival time to ventilator-associated pneumonia, 1.5 days; 95% confidence interval [CI], 0.6 to 2.5; P = 0.004). An infection-related ventilator-associated complication occurred in 74 patients (18%) in the amikacin group and in 111 patients (26%) in the placebo group (hazard ratio, 0.66; 95% CI, 0.50 to 0.89). Trial-related serious adverse effects were seen in 7 patients (1.7%) in the amikacin group and in 4 patients (0.9%) in the placebo group. CONCLUSIONS: Among patients who had undergone mechanical ventilation for at least 3 days, a subsequent 3-day course of inhaled amikacin reduced the burden of ventilator-associated pneumonia during 28 days of follow-up. (Funded by the French Ministry of Health; AMIKINHAL ClinicalTrials.gov number, NCT03149640; EUDRA Clinical Trials number, 2016-001054-17.).

Intravenous Doxycycline, Azithromycin, or Both for Severe Scrub Typhus.

BACKGROUND: The appropriate antibiotic treatment for severe scrub typhus, a neglected but widespread reemerging zoonotic infection, is unclear. METHODS: In this multicenter, double-blind, randomized, controlled trial, we compared the efficacy of intravenous doxycycline, azithromycin, or a combination of both in treating severe scrub typhus. Patients who were 15 years of age or older with severe scrub typhus with at least one organ involvement were enrolled. The patients were assigned to receive a 7-day course of intravenous doxycycline, azithromycin, or both (combination therapy). The primary outcome was a composite of death from any cause at day 28, persistent complications at day 7, and persistent fever at day 5. RESULTS: Among 794 patients (median age, 48 years) who were included in the modified intention-to-treat analysis, complications included those that were respiratory (in 62%), hepatic (in 54%), cardiovascular (in 42%), renal (in 30%), and neurologic (in 20%). The use of combination therapy resulted in a lower incidence of the composite primary outcome than the use of doxycycline (33% and 47%, respectively), for a risk difference of -13.3 percentage points (95% confidence interval [CI], -21.6 to -5.1; P = 0.002). The incidence with combination therapy was also lower than that with azithromycin (48%), for a risk difference of -14.8 percentage points (95% CI, -23.1 to -6.5; P<0.001). No significant difference was seen between the azithromycin and doxycycline groups (risk difference, 1.5 percentage points; 95% CI, -7.0 to 10.0; P = 0.73). The results in the per-protocol analysis were similar to those in the primary analysis. Adverse events and 28-day mortality were similar in the three groups. CONCLUSIONS: Combination therapy with intravenous doxycycline and azithromycin was a better therapeutic option for the treatment of severe scrub typhus than monotherapy with either drug alone. (Funded by the India Alliance and Wellcome Trust; INTREST Clinical Trials Registry-India number, CTRI/2018/08/015159.).

Antibiotic Prophylaxis in Infants with Grade III, IV, or V Vesicoureteral Reflux.

BACKGROUND: The efficacy of continuous antibiotic prophylaxis in preventing urinary tract infection (UTI) in infants with grade III, IV, or V vesicoureteral reflux is controversial. METHODS: In this investigator-initiated, randomized, open-label trial performed in 39 European centers, we randomly assigned infants 1 to 5 months of age with grade III, IV, or V vesicoureteral reflux and no previous UTIs to receive continuous antibiotic prophylaxis (prophylaxis group) or no treatment (untreated group) for 24 months. The primary outcome was the occurrence of the first UTI during the trial period. Secondary outcomes included new kidney scarring and the estimated glomerular filtration rate (GFR) at 24 months. RESULTS: A total of 292 participants underwent randomization (146 per group). Approximately 75% of the participants were male; the median age was 3 months, and 235 participants (80.5%) had grade IV or V vesicoureteral reflux. In the intention-to-treat analysis, a first UTI occurred in 31 participants (21.2%) in the prophylaxis group and in 52 participants (35.6%) in the untreated group (hazard ratio, 0.55; 95% confidence interval [CI], 0.35 to 0.86; P = 0.008); the number needed to treat for 2 years to prevent one UTI was 7 children (95% CI, 4 to 29). Among untreated participants, 64.4% had no UTI during the trial. The incidence of new kidney scars and the estimated GFR at 24 months did not differ substantially between the two groups. Pseudomonas species, other non-Escherichia coli organisms, and antibiotic resistance were more common in UTI isolates obtained from participants in the prophylaxis group than in isolates obtained from those in the untreated group. Serious adverse events were similar in the two groups. CONCLUSIONS: In infants with grade III, IV, or V vesicoureteral reflux and no previous UTIs, continuous antibiotic prophylaxis provided a small but significant benefit in preventing a first UTI despite an increased occurrence of non-E. coli organisms and antibiotic resistance. (Funded by the Italian Ministry of Health and others; PREDICT ClinicalTrials.gov number, NCT02021006; EudraCT number, 2013-000309-21.).

Ceftobiprole for Treatment of Complicated Staphylococcus aureus Bacteremia.

BACKGROUND: Ceftobiprole is a cephalosporin that may be effective for treating complicated Staphylococcus aureus bacteremia, including methicillin-resistant S. aureus. METHODS: In this phase 3, double-blind, double-dummy, noninferiority trial, adults with complicated S. aureus bacteremia were randomly assigned in a 1:1 ratio to receive ceftobiprole at a dose of 500 mg intravenously every 6 hours for 8 days and every 8 hours thereafter, or daptomycin at a dose of 6 to 10 mg per kilogram of body weight intravenously every 24 hours plus optional aztreonam (at the discretion of the trial-site investigators). The primary outcome, overall treatment success 70 days after randomization (defined as survival, bacteremia clearance, symptom improvement, no new S. aureus bacteremia-related complications, and no receipt of other potentially effective antibiotics), with a noninferiority margin of 15%, was adjudicated by a data review committee whose members were unaware of the trial-group assignments. Safety was also assessed. RESULTS: Of 390 patients who underwent randomization, 387 (189 in the ceftobiprole group and 198 in the daptomycin group) had confirmed S. aureus bacteremia and received ceftobiprole or daptomycin (modified intention-to-treat population). A total of 132 of 189 patients (69.8%) in the ceftobiprole group and 136 of 198 patients (68.7%) in the daptomycin group had overall treatment success (adjusted difference, 2.0 percentage points; 95% confidence interval [CI], -7.1 to 11.1). Findings appeared to be consistent between the ceftobiprole and daptomycin groups in key subgroups and with respect to secondary outcomes, including mortality (9.0% and 9.1%, respectively; 95% CI, -6.2 to 5.2) and the percentage of patients with microbiologic eradication (82.0% and 77.3%; 95% CI, -2.9 to 13.0). Adverse events were reported in 121 of 191 patients (63.4%) who received ceftobiprole and 117 of 198 patients (59.1%) who received daptomycin; serious adverse events were reported in 36 patients (18.8%) and 45 patients (22.7%), respectively. Gastrointestinal adverse events (primarily mild nausea) were more frequent with ceftobiprole. CONCLUSIONS: Ceftobiprole was noninferior to daptomycin with respect to overall treatment success in patients with complicated S. aureus bacteremia. (Funded by Basilea Pharmaceutica International and the U.S. Department of Health and Human Services; ERADICATE ClinicalTrials.gov number, NCT03138733.).

Azithromycin to Prevent Sepsis or Death in Women Planning a Vaginal Birth.

BACKGROUND: The use of azithromycin reduces maternal infection in women during unplanned cesarean delivery, but its effect on those with planned vaginal delivery is unknown. Data are needed on whether an intrapartum oral dose of azithromycin would reduce maternal and offspring sepsis or death. METHODS: In this multicountry, placebo-controlled, randomized trial, we assigned women who were in labor at 28 weeks' gestation or more and who were planning a vaginal delivery to receive a single 2-g oral dose of azithromycin or placebo. The two primary outcomes were a composite of maternal sepsis or death and a composite of stillbirth or neonatal death or sepsis. During an interim analysis, the data and safety monitoring committee recommended stopping the trial for maternal benefit. RESULTS: A total of 29,278 women underwent randomization. The incidence of maternal sepsis or death was lower in the azithromycin group than in the placebo group (1.6% vs. 2.4%), with a relative risk of 0.67 (95% confidence interval [CI], 0.56 to 0.79; P<0.001), but the incidence of stillbirth or neonatal death or sepsis was similar (10.5% vs. 10.3%), with a relative risk of 1.02 (95% CI, 0.95 to 1.09; P = 0.56). The difference in the maternal primary outcome appeared to be driven mainly by the incidence of sepsis (1.5% in the azithromycin group and 2.3% in the placebo group), with a relative risk of 0.65 (95% CI, 0.55 to 0.77); the incidence of death from any cause was 0.1% in the two groups (relative risk, 1.23; 95% CI, 0.51 to 2.97). Neonatal sepsis occurred in 9.8% and 9.6% of the infants, respectively (relative risk, 1.03; 95% CI, 0.96 to 1.10). The incidence of stillbirth was 0.4% in the two groups (relative risk, 1.06; 95% CI, 0.74 to 1.53); neonatal death within 4 weeks after birth occurred in 1.5% in both groups (relative risk, 1.03; 95% CI, 0.86 to 1.24). Azithromycin was not associated with a higher incidence in adverse events. CONCLUSIONS: Among women planning a vaginal delivery, a single oral dose of azithromycin resulted in a significantly lower risk of maternal sepsis or death than placebo but had little effect on newborn sepsis or death. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; A-PLUS ClinicalTrials.gov number, NCT03871491.).

Trial of Vancomycin and Cefazolin as Surgical Prophylaxis in Arthroplasty.

BACKGROUND: The addition of vancomycin to beta-lactam prophylaxis in arthroplasty may reduce surgical-site infections; however, the efficacy and safety are unclear. METHODS: In this multicenter, double-blind, superiority, placebo-controlled trial, we randomly assigned adult patients without known methicillin-resistant Staphylococcus aureus (MRSA) colonization who were undergoing arthroplasty to receive 1.5 g of vancomycin or normal saline placebo, in addition to cefazolin prophylaxis. The primary outcome was surgical-site infection within 90 days after surgery. RESULTS: A total of 4239 patients underwent randomization. Among 4113 patients in the modified intention-to-treat population (2233 undergoing knee arthroplasty, 1850 undergoing hip arthroplasty, and 30 undergoing shoulder arthroplasty), surgical-site infections occurred in 91 of 2044 patients (4.5%) in the vancomycin group and in 72 of 2069 patients (3.5%) in the placebo group (relative risk, 1.28; 95% confidence interval [CI], 0.94 to 1.73; P = 0.11). Among patients undergoing knee arthroplasty, surgical-site infections occurred in 63 of 1109 patients (5.7%) in the vancomyin group and in 42 of 1124 patients (3.7%) in the placebo group (relative risk, 1.52; 95% CI, 1.04 to 2.23). Among patients undergoing hip arthroplasty, surgical-site infections occurred in 28 of 920 patients (3.0%) in the vancomyin group and in 29 of 930 patients (3.1%) in the placebo group (relative risk, 0.98; 95% CI, 0.59 to 1.63). Adverse events occurred in 35 of 2010 patients (1.7%) in the vancomycin group and in 35 of 2030 patients (1.7%) in the placebo group, including hypersensitivity reactions in 24 of 2010 patients (1.2%) and 11 of 2030 patients (0.5%), respectively (relative risk, 2.20; 95% CI, 1.08 to 4.49), and acute kidney injury in 42 of 2010 patients (2.1%) and 74 of 2030 patients (3.6%), respectively (relative risk, 0.57; 95% CI, 0.39 to 0.83). CONCLUSIONS: The addition of vancomycin to cefazolin prophylaxis was not superior to placebo for the prevention of surgical-site infections in arthroplasty among patients without known MRSA colonization. (Funded by the Australian National Health and Medical Research Council; Australian New Zealand Clinical Trials Registry number, ACTRN12618000642280.).

The NLRP3 Inflammasome Is a Major Cause of Acute Renal Failure Induced by Polypeptide Antibiotics.

Drug-induced acute renal failure (ARF) is a public health concern that hinders optimal drug therapy. However, pathological mechanisms of drug-induced ARF remain to be elucidated. Here, we show that a pathological process of drug-induced ARF is mediated by proinflammatory cross-talk between kidney tubular cells and macrophages. Both polymyxin B and colistin, polypeptide antibiotics, frequently cause ARF, stimulated the ERK and NF-κB pathways in kidney tubular cells, and thereby upregulated M-CSF and MCP-1, leading to infiltration of macrophages into the kidneys. Thereafter, the kidney-infiltrated macrophages were exposed to polypeptide antibiotics, which initiated activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome. Interestingly, blockade of the NLRP3 activation clearly ameliorated the pathology of ARF induced by polypeptide antibiotics, suggesting that a combination of the distinct cellular responses to polypeptide antibiotics in kidney tubular cells and macrophages plays a key role in the pathogenesis of colistin-induced ARF. Thus, our results provide a concrete example of how drugs initiate ARF, which may give insight into the underlying pathological process of drug-induced ARF.

Peptic ulcer disease.

Annual prevalence estimates of peptic ulcer disease range between 0·12% and 1·5%. Peptic ulcer disease is usually attributable to Helicobacter pylori infection, intake of some medications (such as aspirin and non-steroidal anti-inflammatory medications), or being critically ill (stress-related), or it can be idiopathic. The clinical presentation is usually uncomplicated, with peptic ulcer disease management based on eradicating H pylori if present, the use of acid-suppressing medications-most often proton pump inhibitors (PPIs)-or addressing complications, such as with early endoscopy and high-dose PPIs for peptic ulcer bleeding. Special considerations apply to patients on antiplatelet and antithrombotic agents. H pylori treatment has evolved, with the choice of regimen dictated by local antibiotic resistance patterns. Indications for primary and secondary prophylaxis vary across societies; most suggest PPIs for patients at highest risk of developing a peptic ulcer, its complications, or its recurrence. Additional research areas include the use of potassium-competitive acid blockers and H pylori vaccination; the optimal approach for patients at risk of stress ulcer bleeding requires more robust determinations of optimal patient selection and treatment selection, if any. Appropriate continuation of PPI use outweighs most possible side-effects if given for approved indications, while de-prescribing should be trialled when a definitive indication is no longer present.

SER-109, an Oral Microbiome Therapy for Recurrent Clostridioides difficile Infection.

BACKGROUND: Current therapies for recurrent Clostridioides difficile infection do not address the disrupted microbiome, which supports C. difficile spore germination into toxin-producing bacteria. SER-109 is an investigational microbiome therapeutic composed of purified Firmicutes spores for the treatment of recurrent C. difficile infection. METHODS: We conducted a phase 3, double-blind, randomized, placebo-controlled trial in which patients who had had three or more episodes of C. difficile infection (inclusive of the qualifying acute episode) received SER-109 or placebo (four capsules daily for 3 days) after standard-of-care antibiotic treatment. The primary efficacy objective was to show superiority of SER-109 as compared with placebo in reducing the risk of C. difficile infection recurrence up to 8 weeks after treatment. Diagnosis by toxin testing was performed at trial entry, and randomization was stratified according to age and antibiotic agent received. Analyses of safety, microbiome engraftment, and metabolites were also performed. RESULTS: Among the 281 patients screened, 182 were enrolled. The percentage of patients with recurrence of C. difficile infection was 12% in the SER-109 group and 40% in the placebo group (relative risk, 0.32; 95% confidence interval [CI], 0.18 to 0.58; P<0.001 for a relative risk of <1.0; P<0.001 for a relative risk of <0.833). SER-109 led to less frequent recurrence than placebo in analyses stratified according to age stratum (relative risk, 0.24 [95% CI, 0.07 to 0.78] for patients <65 years of age and 0.36 [95% CI, 0.18 to 0.72] for those ≥65 years) and antibiotic received (relative risk, 0.41 [95% CI, 0.22 to 0.79] with vancomycin and 0.09 [95% CI, 0.01 to 0.63] with fidaxomicin). Most adverse events were mild to moderate and were gastrointestinal in nature, with similar numbers in the two groups. SER-109 dose species were detected as early as week 1 and were associated with bile-acid profiles that are known to inhibit C. difficile spore germination. CONCLUSIONS: In patients with symptom resolution of C. difficile infection after treatment with standard-of-care antibiotics, oral administration of SER-109 was superior to placebo in reducing the risk of recurrent infection. The observed safety profile of SER-109 was similar to that of placebo. (Funded by Seres Therapeutics; ECOSPOR III ClinicalTrials.gov number, NCT03183128.).

Oral Tebipenem Pivoxil Hydrobromide in Complicated Urinary Tract Infection.

BACKGROUND: There is a need for oral antibiotic agents that are effective against multidrug-resistant gram-negative uropathogens. Tebipenem pivoxil hydrobromide is an orally bioavailable carbapenem with activity against uropathogenic Enterobacterales, including extended-spectrum beta-lactamase-producing and fluoroquinolone-resistant strains. METHODS: In this phase 3, international, double-blind, double-dummy trial, we evaluated the efficacy and safety of orally administered tebipenem pivoxil hydrobromide as compared with intravenous ertapenem in patients with complicated urinary tract infection or acute pyelonephritis. Patients were randomly assigned, in a 1:1 ratio, to receive oral tebipenem pivoxil hydrobromide (at a dose of 600 mg every 8 hours) or intravenous ertapenem (at a dose of 1 g every 24 hours) for 7 to 10 days (or up to 14 days in patients with bacteremia). The primary efficacy end point was overall response (a composite of clinical cure and favorable microbiologic response) at a test-of-cure visit (on day 19, within a ±2-day window) in the microbiologic intention-to-treat population. The noninferiority margin was 12.5%. RESULTS: A total of 1372 hospitalized adult patients were enrolled; 868 patients (63.3%) were included in the microbiologic intention-to-treat population (50.8% of whom had complicated urinary tract infections and 49.2% of whom had pyelonephritis). An overall response was seen in 264 of 449 patients (58.8%) who received tebipenem pivoxil hydrobromide, as compared with 258 of 419 patients (61.6%) who received ertapenem (weighted difference, -3.3 percentage points; 95% confidence interval [CI], -9.7 to 3.2). Clinical cure at the test-of-cure visit was observed in 93.1% of the patients in the microbiologic intention-to-treat population who received tebipenem pivoxil hydrobromide and 93.6% of patients who received ertapenem (weighted difference, -0.6 percentage point; 95% CI, -4.0 to 2.8); the majority of patients with microbiologic response failures at the test-of-cure visit were asymptomatic patients with recurrent bacteriuria. Secondary and subgroup analyses were supportive of the primary analysis. Adverse events were observed in 25.7% of patients who received tebipenem pivoxil hydrobromide and in 25.6% of patients who received ertapenem; the most common adverse events were mild diarrhea and headache. CONCLUSIONS: Oral tebipenem pivoxil hydrobromide was noninferior to intravenous ertapenem in the treatment of complicated urinary tract infection and acute pyelonephritis and had a similar safety profile. (Funded by Spero Therapeutics and the Department of Health and Human Services; ADAPT-PO ClinicalTrials.gov number, NCT03788967.).

Chimeric peptidomimetic antibiotics against Gram-negative bacteria.

There is an urgent need for new antibiotics against Gram-negative pathogens that are resistant to carbapenem and third-generation cephalosporins, against which antibiotics of last resort have lost most of their efficacy. Here we describe a class of synthetic antibiotics inspired by scaffolds derived from natural products. These chimeric antibiotics contain a ß-hairpin peptide macrocycle linked to the macrocycle found in the polymyxin and colistin family of natural products. They are bactericidal and have a mechanism of action that involves binding to both lipopolysaccharide and the main component (BamA) of the ß-barrel folding complex (BAM) that is required for the folding and insertion of ß-barrel proteins into the outer membrane of Gram-negative bacteria. Extensively optimized derivatives show potent activity against multidrug-resistant pathogens, including all of the Gram-negative members of the ESKAPE pathogens1. These derivatives also show favourable drug properties and overcome colistin resistance, both in vitro and in vivo. The lead candidate is currently in preclinical toxicology studies that-if successful-will allow progress into clinical studies that have the potential to address life-threatening infections by the Gram-negative pathogens, and thus to resolve a considerable unmet medical need.

Antimicrobial Drug Penetration Is Enhanced by Lung Tissue Inflammation and Injury.

Rationale: Pneumonia is a frequent and feared complication in intubated critically ill patients. Tissue concentrations of antimicrobial drugs need to be sufficiently high to treat the infection and also prevent development of bacterial resistance. It is uncertain whether pulmonary inflammation and injury affect antimicrobial drug penetration into lung tissue.Objectives: To determine and compare tissue and BAL fluid concentrations of ceftaroline fosamil and linezolid in a model of unilateral acute lung injury in pigs and to evaluate whether dose adjustment is necessary to reach sufficient antimicrobial concentrations in injured lung tissue.Methods: After induction of unilateral acute lung injury, ceftaroline fosamil and linezolid were administered intravenously. Drug concentrations were measured in lung tissue through microdialysis and in blood and BAL fluid samples during the following 8 hours. The primary endpoint was the tissue concentration area under the concentration curve in the first 8 hours (AUC0-8 h) of the two antimicrobial drugs.Measurements and Main Results: In 10 pigs, antimicrobial drug concentrations were higher in inflamed and injured lung tissue compared with those in uninflamed and uninjured lung tissue (median ceftaroline fosamil AUC0-8 h [and interquartile range] = 26.7 mg ⋅ h ⋅ L-1 [19.7-39.0] vs. 16.0 mg ⋅ h ⋅ L-1 [13.6-19.9], P = 0.02; median linezolid AUC0-8 h 76.0 mg ⋅ h ⋅ L-1 [68.1-96.0] vs. 54.6 mg ⋅ h ⋅ L-1 [42.7-60.9], P = 0.01), resulting in a longer time above the minimal inhibitory concentration and in higher peak concentrations and dialysate/plasma ratios. Penetration into BAL fluid was excellent for both antimicrobials, but without left-to-right differences (ceftaroline fosamil, P = 0.78; linezolid, P = 1.00).Conclusions: Tissue penetration of two commonly used antimicrobial drugs for pneumonia is enhanced by early lung tissue inflammation and injury, resulting in longer times above the minimal inhibitory concentration. Thus, lung tissue inflammation ameliorates antimicrobial drug penetration during the acute phase.

In complicated UTIs, cefepime-taniborbactam increased treatment success vs. meropenem at 19 to 23 d.

SOURCE CITATION: Wagenlehner FM, Gasink LB, McGovern PC, et al; CERTAIN-1 Study Team. Cefepime-taniborbactam in complicated urinary tract infection. N Engl J Med. 2024;390:611-622. 38354140.

Antibiotics taken within the first year of life are linked to infant gut microbiome disruption and elevated atopic dermatitis risk.

BACKGROUND: Atopic dermatitis (AD) is the most common chronic inflammatory skin disease in both pediatric and adult populations. The development of AD has been linked to antibiotic usage, which causes perturbation of the microbiome and has been associated with abnormal immune system function. However, imbalances in the gut microbiome itself associated with antibiotic usage have been inconsistently linked to AD. OBJECTIVES: This study aimed to elucidate the timing and specific factors mediating the relationship between systemic (oral or intravenous) antibiotic usage and AD. METHODS: We used statistical modeling and differential analysis to link CHILD Cohort Study participants' history of antibiotic usage and early-life gut microbiome alterations to AD. RESULTS: Here we report that systemic antibiotics during the first year of life, as compared to later, are associated with AD risk (adjusted odds ratio [aOR] = 1.81; 95% CI: 1.28-2.57; P < .001), with an increased number of antibiotic courses corresponding to a dose response-like increased risk of AD risk (1 course: aOR: 1.67; 95% CI: 1.17-2.38; 2 or more courses: aOR: 2.16; 95% CI: 1.30-3.59). Further, we demonstrate that microbiome alterations associated with both AD and systemic antibiotic usage fully mediate the effect of antibiotic usage on the development of AD (ßindirect = 0.072; P < .001). Alterations in the 1-year infant gut microbiome of participants who would later develop AD included increased Tyzzerella nexilis, increased monosaccharide utilization, and parallel decreased Bifidobacterium and Eubacterium spp, and fermentative pathways. CONCLUSIONS: These findings indicate that early-life antibiotic usage, especially in the first year of life, modulates key gut microbiome components that may be used as markers to predict and possibly prevent the development of AD.

Hepatotoxicity of Antibiotics and Antifungals and Their Safe Use in Hepatic Impairment.

Idiosyncratic drug-induced liver injury (DILI) is a rare and unpredictable form of hepatotoxicity. While its clinical course is usually benign, cases leading to liver transplantation or death can occur. Based on modern prospective registries, antimicrobials including antibiotics and antifungals are frequently implicated as common causes. Amoxicillin-clavulanate ranks as the most common cause for DILI in the Western World. Although the absolute risk of hepatotoxicity of these agents is low, as their usage is quite high, it is not uncommon for practitioners to encounter liver injury following the initiation of antibiotic or antifungal therapy. In this review article, mechanisms of hepatoxicity are presented. The adverse hepatic effects of well-established antibiotic and antifungal agents are described, including their frequency, severity, and pattern of injury and their HLA risks. We also review the drug labeling and prescription guidance from regulatory bodies, with a focus on individuals with hepatic impairment.

Skeletal Muscle Proteome Modifications following Antibiotic-Induced Microbial Disturbances in Cancer Cachexia.

Cancer cachexia is an involuntary loss of body weight, mostly of skeletal muscle. Previous research favors the existence of a microbiota-muscle crosstalk, so the aim of the study was to evaluate the impact of microbiota alterations induced by antibiotics on skeletal muscle proteins expression. Skeletal muscle proteome changes were investigated in control (CT) or C26 cachectic mice (C26) with or without antibiotic treatment (CT-ATB or C26-ATB, n = 8 per group). Muscle protein extracts were divided into a sarcoplasmic and myofibrillar fraction and then underwent label-free liquid chromatography separation, mass spectrometry analysis, Mascot protein identification, and METASCAPE platform data analysis. In C26 mice, the atrogen mafbx expression was 353% higher than CT mice and 42.3% higher than C26-ATB mice. No effect on the muscle protein synthesis was observed. Proteomic analyses revealed a strong effect of antibiotics on skeletal muscle proteome outside of cachexia, with adaptative processes involved in protein folding, growth, energy metabolism, and muscle contraction. In C26-ATB mice, proteome adaptations observed in CT-ATB mice were blunted. Differentially expressed proteins were involved in other processes like glucose metabolism, oxidative stress response, and proteolysis. This study confirms the existence of a microbiota-muscle axis, with a muscle response after antibiotics that varies depending on whether cachexia is present.